On May 29, 1919, the young English astronomer Arthur Eddington (December 28, 1882–November 22, 1944) catapulted Albert Einstein into celebrity by proving the most significant scientific model of the universe since Newtonian gravity: the general theory of relativity, completed four years earlier. For a quarter millennium, Newton’s conception of space as static and absolute had gone unquestioned. According to his instantaneous-action-at-a-distance theory, gravity is a force that, like magnetism, acts through space but not on space, and light travels only…